Office 365 not connecting with SBS 2011 server on network

We recently moved our email (6 users) from Exchange on SBS 2011 to Office 365 but we are still using the server as a file server. We changed the dns of each computer to point to the gateway but intermittently Outlook 2013 is trying to resolve to the SBS server, not Office 365 ( and email will not connect. Any suggestions?
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Andrew CeohanSys & Net AdminCommented:
When you setup O365, did you also change the internal/external DNS records to point to O365 and not your old Exchange server?
Cliff GaliherCommented:
Outlook uses autodiscovery to find the exchange server it should connect to. DNS is only tried if an AD object is not found. And in SBS, that AD object exists and will try to reclaim connections.

In other words, SBS is messing with you. Retire it; it is near EOL anyways. Go all cloud or migrate domain and file services to a non-SBS server with a newer OS. That will solve your issue if SBS is decommissioned properly.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
DavidAuthor Commented:
Thanks. External DNS has been changed as email works intermittently (for a day or so). We are planning to move to the Cloud but it will take us another month to get through that process.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Microsoft Office

From novice to tech pro — start learning today.